• Tag : ECMP


Exposing ECMP hashing algorithm details

I need to determine the ECMP path (route) to be taken by a specific packet (combination of packet header fields). I use an Arista 7050TX switch with EOS v. 4.18.6M . It seems there is a command in config mode (show load-balance destination ingress-interface {used header fields}) which helps determine the outgoing interface for a specific packet. The Arista blog post however is not publicly visible. Could someone provide a detailed explanation of the command? Alternatively and preferably, I would like to reproduce the hashing algorithm behaviour. My attempts to track that so far bare no results. I can set...
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MLAG ECMP load balance method

Hello, I need a help with proper design. I have a pair 7050X with MLAG configuration. To the downstream devices I have 2 mlag port-channels each contain 2 links. 7050X will provide L3 functionality : gateways and routing.  I would like to enabling ecmp and load-balance the traffic. What will be the best method to choose in this scenario ?   Thank you

Arista 7280QR-C36 Load Balancing Optimization for Dual Homed Systems and Networks

Arista 7280QR-C36  The Arista DCS-7280QR-C36 switch is a purpose built flexible fixed configuration 1RU system capable of supporting a wide range of interface choices. Its designed for the highest performance environments such as IP Storage, Content Delivery Networks, Data Center Interconnect and IP Peering. The 7280QR-C36 is optimized for environments with dual connected nodes such as storage and for spine applications with dual homed leaf switches. This technical application note describes the internal optimized load-balancing mechanism used within the switch and how network architects can best deploy this system to maximize overall system performance. The internal architecture of the DCS-7280QR-C36...
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Load Balancing with ECMP: Hardware Configuration Lookup

Abstract: This publication illustrates a technique which can be used to find exactly how Arista devices program routes to send traffic across multiple available paths. An example will be given on the Arista DCS-7150S-52-CL-R running EOS version 4.14.8M. Initial configuration: As an IGP we are using OSPF with maximum paths feature configured: Arista(config)#router ospf 1 Arista(config-router-ospf)#maximum-paths 32 There are two iBGP peers configured via a peer-group “pg1”: Arista(config)#router bgp 65001 Arista(config-router-bgp)#neighbor pg1 maximum-routes 16000 Arista(config-router-bgp)#neighbor peer-group pg1 Arista(config-router-bgp)#neighbor peer-group pg1 iBGP advertisements: * >    0       100     0       64920 64944...
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Fabric Visibility

A leaf and spine fabric is challenging to monitor. The fabric spreads traffic across all the switches and links in order to maximize bandwidth. Unlike traditional hierarchical network designs, where a small number of links can be monitored to provide visibility, a leaf and spine network has no special links or switches where running CLI commands or attaching a probe would provide visibility. Even if it were possible to attach probes, the effective bandwidth of a leaf and spine network can be as high as a Petabit/second, well beyond the capabilities of current generation monitoring tools. The 2 minute video...
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